Path: news.easynews.com!newsfeed1.easynews.com!newsfeed2.easynews.com!easynews.com!easynews!newsfeed.news2me.com!newsfeed.icl.net!newsfeed.fjserv.net!kibo.news.demon.net!news.demon.co.uk!demon!not-for-mail From: "Jonathan Lewis" Newsgroups: comp.databases.oracle.server Subject: Re: How "deterministic" are EXPLAIN PLAN results? Date: Thu, 10 Apr 2003 12:46:18 +0100 Lines: 52 Message-ID: References: <27270a53.0304090254.6c48b3f@posting.google.com> <336da121.0304090721.4a4f407a@posting.google.com> <1jk89vo64iubghsbnb6o6aro39l8njo44i@4ax.com> NNTP-Posting-Host: jlcomp.demon.co.uk X-Trace: news.demon.co.uk 1049975145 27644 158.152.75.41 (10 Apr 2003 11:45:45 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Thu, 10 Apr 2003 11:45:45 +0000 (UTC) X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 X-Priority: 3 X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MSMail-Priority: Normal Xref: newsfeed1.easynews.com comp.databases.oracle.server:182831 X-Received-Date: Thu, 10 Apr 2003 04:45:25 MST (news.easynews.com) His information is a little out of date, anyway. There is a hidden parameter that controls whether the session level optimizer mode is pushed into PL/SQL or not. Somewhere around 8.1.6/7 its default value was changed from false to true -- Regards Jonathan Lewis http://www.jlcomp.demon.co.uk The educated person is not the person who can answer the questions, but the person who can question the answers -- T. Schick Jr One-day tutorials: http://www.jlcomp.demon.co.uk/tutorial.html ____UK_______April 22nd ____Denmark__May 21-23rd ____USA_(FL)_May 2nd Three-day seminar: see http://www.jlcomp.demon.co.uk/seminar.html ____UK_(Manchester)_May ____Estonia___June (provisional) ____Australia_June (provisional) ____USA_(CA, TX)_August The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html "Vladimir M. Zakharychev" wrote in message news:b73k6u$462$1@babylon.agtel.net... > > Actually, what Sybrand probably meant is that the OPTIMIZER_MODE > setting is ignored in PL/SQL and is always assumed ALL_ROWS. > But to my knowledge hints are not ignored, so if you hint your > query with /*+ FIRST_ROWS */, it will be executed in this mode > by both PL/SQL and SQL engines. By the way, this may not apply > to 9i since PL/SQL and SQL use the same engine in 9i. >